Oil separator



25, 1952 s. w. BRIGGS 2,608,269

OIL SEPARATOR Filed April 6, 1948 2 SHEETSSI-IEET 1 O I 8 I 6 I I g 7 Vt I I I I: I I f*\ Z\ I 1 ll "Q 1 I a I I I I I I I l I I -57 mum '2 2 1II II I 2 64 Mae III III J :6

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S. W. BRiGGS OIL SEPARATOR Aug. 26, 1952 2 SHEETS'SHEET 2 Filed April 6,1948 C ONDENSEB sxPmvslo/v m 1. vs

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Patented Aug. 26, 1952 UNITED T TES ATENT OFF-ice;j;

I Southwick w. Briggs, Bethesda, Md. ApplicationApril 6, 1948, SerialNo. 19,264

This invention relates to apparatus for the removal of entrained liquidfrom gases and more particularly for the separation ofoil from arefrigerant. I

In the usual refrigeration apparatus the refrigerant is compressed .to arelatively high pressure in a reciprocating; or rotary compressor. Thecompressed refrigerant in a substantially gaseous condition is thenintroduced into a condenser Which removes the heat of compression andcondenses the refrigerant. The cooled, condensed refrigerant isthrottled through an expansion valve which lowers its temperature andisthen introduced into an, evaporator in" which it absorbs heat from.the material to be cooled. The gaseous refrigerant from the evaporatoris returned to the compressor torepeat-the cycle.

The heat given up by the material to, be cooled and. the heat introducedinto the cycle by the compression of the refrigerant must be removedfrom the refrigerant in the condenser. In order to, reduce the cost andsize of the apparatus, it is highly desirable to have a high rate ofheat transfer in the condenser. The refrigerant discharged from thecompressor, however, is generally contaminated with entrained oil whichcoats the heat transfer surfaces in the condenser and reduces its heat.transfer capacity. The presence of a film of oil on the heat transfersurfaces of the condenser may reduce its capaciiw asmuch as25%. o u Theoil separators heretofore available have not removed oil from therefrigerant completely enough to prevent the formation of an oil film inthe condensers. t has, therefore, been necessary. to over-design thecondenser capacity to make allowance forthe low rate of heat transfer.Furthermoraxthe separators'of the prior art have not removed water from,the refrigerant and hydrolysis of the refrigerant withserious corrosionof: the refrigeration equipment has resulted. Moreover, the separatorsheretofore available generally fail by by-passing refrigerant from theseparator directly back to the crankcase of the compressor. It is thennot possible to pull the vacuum on the evaporator and the pressure andtemperature in theevaporator areincreased.

; It is an object of this invention to remove entrained and dissolvedoil from the refrigerant-discharged froma compressor of a refrigeratingmachine prior to the cooling of thegrefrigerant. V

It is also an object of this invention to remove traces of water fromthe-refrigerant and oil in a refrigerating machine. 7 I Another objectof this inventionis to remove 6 Claims. (01. 183-42) from by-passingtheadsorbent block.

impurities such as gums and carbon from the lubricating oil used in thecompressor of arefrigerating machine.

A further object of this invention is to provide apparatus for theefficient separation and separate discharging of liquids and gasesfromrnixtures thereof.

Still another object of this invention is to provide means fordischarging separated oil without passing gaseous refrigerant directlyfrom the separator to the compressor. y 1

With these and other objects in mind which will become apparent in thefollowing detailed description of the invention, this invention tresidesin a porousadsorbent block through which the refrigerant dischargedfrornthe compressor must pass before enteringthe -condenser a refrigeratingmachine. Provision is'made t direct the flow of the refrigerant to aidthe :sepa} ration of droplets of liquid from thevgaseousijefrigerantpassing through the oil separator. While this invention is described forthe separation of lubricating oil from refrigerants, it will beappreciated that the apparatus is efficientfor the separationof liquidsfrom gases generally, and is particularly efficient in the' separatio'riof liquids from gases which are substantially, insolubleinthe liquids. Y

Inthe drawings:

Figure 1 is a vertical sectional view offthe oil separator of thisinvention. a I '5 Figure 2 isa schematic flow sheet of refrigerat ingapparatus showing the location of the oil separator inthe apparatus. I

Figure 3 is a detailed sectional view of a float operated valve fordischarging the separated Jo'il from the separator; and Figure 4 is asectional View illustrating, made. tail the closure means to preventthelrefri era'rft As is best illustrated inFi'gure 2, th eoilisepafrator of this invention .is preferably'iinstalled between thecompressor-and "condenser vofaf'refrigerating machine. If;

} Referring to Figure L'the oil'separator of this inventionisillustrated in a casing: I, having a base 2 integral therewithandadorned 'coverff3 closing its upper end. Cover 3' is seeurai-gt casing iby means of nuts 6 engaging. studs 5j wh'ich extend upwardly from aflange 6 att'ached'to the .upper end of the casing i. ,A gasket ,1'on'the upper rim of casingll prevents leakage" betw n the casing andthe cover. An inlet Sandanoutlet 9 are provided in,

a a 'i efi Qfli e i e n tim their separator. An outlet tube Icommunicates with outlet 9 which is substantially centrally located inthe cover and extends downwardly therefrom into the casing I. Outlettube I0 opens downwardly in a container I I secured to its lower end.Container I I occupies substantially the full crosssectional area of thecasing and is also open at its lower end I2. The upper end I3 and wallsI4 of the container areimperforate, thereby forcing thefluid'passing-through container; II to enter its open lower end I2 andleave through the outlet I0.

Upper end I3 of container II provides a surface on which a helicalspring I5 surrounding-the ,andcalso to serve as a valve seat preventingflow outlet tube l0 rests. Helical spring l5 is.in a compressedcondition during the operation of the oil separator and bearsagainstawasher; I.6;-which is slidable along the outer surface of outlettube I0. Washer I6 engagesia sealing rin II-of compressible materialwhich closes the openings between-the outer surface ofroutlet tube I-IIand-a "plate I8 slidable ontube I0.

A porous adsorbent tubular-'block I29 having-a central bore is supportedby .plate l8 :which urges the block against the lower surface-of-jthecover-f the oil separator. Outlet tube l o'passes through the centralbore of the adsorbent block I 9. Flow of the refrigerant past 'theends'of' the "adsorbentblock is preventedby-gaskets Z'I and 22 attheupper-and lowerends of -the'block, respectively. The central bore 20 ofthe alumina block :communicates with the inlet 8-of the oil separator.

-'ndsorbentblock I9 is --preferabl-y of-activated aluminabondedwith-asuitable inorganic-binder. 5

madsorbent-m'aterialprepared according to'the invention-describedin-mycopending application 'filed'onjduly-il; 1948 and having ser'ial-No."37 ,97-l "entitled "Bon'ded Filter Medium in Y which the aluminaisbonded with Portland cementis highly satisfactory. Porous, adsorbent--blocks bonded with aluminum phosphate 'or sodium silicate bindersarealso-satisfactory. In some instances itim'ay be desirable to providea porousmass of :activated silica .gel;" however, generally-alumina isjleferred. since it doesrnot decrepitate-on contact with'water.

A strainer 23 enclosed in a wiremes'hcoverffl is supported .bywires 25and, 26-in-the,-'iower:end of container II. The*strainer 2'3occupies-thefull cross-sectional are'a of container II =to-;prevent :hy passing .ofthe "refrigerant ,around its sides. As 'mentioned "above, :the containerI I is .of large diameter toprovide "a :conduithavinga largecross-sectional area through which-there- "trigerant may passat a verylow velocity.

In the preferred form, the;strainer23"consists .offi'a massoffine-copperwoo1 which; whilegoftan open 'nature to ;pr,ovide 'alarge free space,also provides an extremely 'lal esurface over which fthe'irefrigerantpasses. In certain instances, such as when "the refrigerantiscorrosiveto copper, *it 'will, of course, be'necessary to'provide astrainer of finely divided material -which 1is-resistant to thecorrosive ,efiects-aoftherefrigerant. If ammonia is "the refrigerant,steel wool,may housed in 'strainer':23.

"frhelower'endof the casing I-jb'elowthestrainer 23 'servesasa 'well "21'forthe collection of oil 'separate'dfrom therefrigerant. :Afloat-operated Valveindicated generallyrby 28, iSiPI'OVidGdY-IJO controlthe discharge of" the-oi1ifrom thewell' in casing I.

, "Float joperated valve *28 consists -'ofr'abody: 29 drilled and"tapped at 3'0 at "its upper end for .horizontally across the .valveforthereception of :a valve stem'35. A port 36 passes through the stem inalignment with passage 33 to allow .flow through the valve when thevalve stem is in the open position. Conduit 34 is machined tovcloseztolerances to allow stem 35 to rotate therein 'through'theyalvewhen port 36 does not com- ;municatewith passage 33.

Valve stem 35 may be held in place within the body-29 of the valve byany suitable means. In the form illustrated, a washer 31 engages agasket =38 in -a recesslin the :body 229 .to fix theposition of the:stem :withimtheibodyrof the :valve. The stem 'isih'eldi'in placebyzmeans of :a bolt ?35 engaging a washer 40. Bolt 39 is screwed intothe end of stem 35. .A fioatllI is connected by means -of anarm '42 tothe stem.35 and rotates'the-stem as thellevel of :the liduidiinzthecwell21 changes.

Ascreen 43 ishe'ldin place across-the lower -end of the valve body 29.toprevent the entrance of-'any'fluid particles which might accumulate in"the wel1' 2'I. Theopenings'in screen. should "preferably beabout 'the:size of passage J33 to prohibit the entrance :of any particles largeenough? to bri'dge across the passage 33 :and preerant-idissolved inthe;lubricant; consequently, .as

the compressor "starts to frun,'.largerslugs 'of .oil "are :dischargedwith fthe refrigerant. rAt fthis time a foam may be:dischargedffromathe. compressor to ='.the separator. :After .thecompressor has operated-for :a 'shortwrperiodga dine :mistx-o'flubricant is generally present in .the refrigerant passing ffrom the;compressor :to :the -..oil ;sepa- The :velocity of rthecoil-la'den;irefrigerant.-'entering the inletil :of the oil separator :is mediately.;reduced:.by the large volume of {the central :Ehore L20 of 'theadsorbent .-.block ito =.pre- 'cipitate: alarge: part of the-:oil.Therefrigerant and the oi1 then:pass through -the:porous:adsorb- .ent:block :and .2816 .-:discharged :from. its :outer surface. If .any Tfoamis present, :it is :broken by contact.-.with Lthe surface of .theadsorbent block 31:9. isimilarly, ganytflnemist of liquid ;is depositedand rcoalesces on the 'surfaces.of :the passages "within "the -block:-as the refrigerant follows: anextremely' tor-tuous path therethrough.The liquid phase, which is largely 'oill-butialso containssomerefrigerant, sweatssfromithe'outer surface :of the porous "block "I9 anddrops from its lower :edge :lin the form of large drops of liquid #whichare easily separated from -the gaseous' phase.

If an adsorbent porous'blok of the type-"described hereinbefore isemployed,:a=number'of advantages in addition Lto the breaking act thefoam andf separation bf -mi'stf-from the gaseous phase are-gained;Arfactivated alumina block, fori example; effectively remove tracesofmoisture from-therefrigerant and oil. The removal'of 'moistureprevents -the hydrolysis of the sir'able that means purities from thelubricant. While only. a-relatively-small portion of the lubricant isdischargedv from the compressor with the' 'refrigerant', thethoroughtreatmentof that portion of the lubricant is suificient toprevent 'the'accumulation of gum and carbon in the crankcase of thecompressor.

. The refrigerant dischargedfromthe outer surface of the adsorbent block19- and the liquid dropping from its lower end pass downwardly in thecasing. The large volume of container II results in the gas flowingdownwardly at an increased velocity. As the gas passes the lower end I2of container H, its direction of flow is changed which tends to throwparticles of mist from the gas into well 21. The large drops of liquidwill, of course, fall readily into the well 21 and accumulate there.

After passing the lower edge l2 of container II, the gaseous phasechanges its direction of flow and then passes upwardly at a low velocitythrough the screen 23. The very large surface and the extremely largenumber of very small passages in the copper wool within the strainerinsures contact of any mist with the surface of the strainer. The lasttraces of the mist are deposited on the strainer, coalesce, and dropinto the well 21. Oil-free refrigerant is discharged from the top ofstrainer 23 into outlet tube It.

The liquid phase collected in the well 21 will containsome refrigerant.Inthe case of Freon-12, for example, which is completely miscible withlubricating oil, a relatively high concentration of refrigerant may bein the liquid collected in wellZ'l. This refrigerant continuallyevaporates from the surface of the collected liquid and passes throughstrainer 23 to the outlet of the separator with the main body ofrefrigerant.

As the level of the liquid collected in well 2'! rises, float 4| will belifted and turn stem 35 until port 35 communicates with passage 3. Theliquid in well 21 will then enter through the lower'end of the valvebody 29 and pass through passage 33 and port 36 to the discharge tube3|. The liquid discharged through tube 3! and opening 43 is returned tothe crankcase of the com.- pressor.

It will be noted that a float operated valve is provided in which thestem and seat of the valve are in sliding contact. In this manner thelodging of a solid particle between the stem and seat is prevented. Inseparators employing float operated needle valves, for example, a solidparticle may lodge in the needle valve. As the be providedtoremovle'imliquidlevel falls, the valve is held open bythe solid particle andeventually gas is returned from the oil'separator to "the crankcase ofthe-compressor. The compressor is then'not able to pull a vacuum on theevaporator and'the'cap'acity ofthe refrigerating machine is reduced. i I

The refrigerant passing from' outlet fi t'othe condenser is virtuallyoil-free. Anyoil present will be dissolved by the refrigerant-andwill-not collect in the-condenser to form a film on its surfaces. Thiseffective removal of theoil'from the condenser surfaces allows thecapacity of the condenser to be increased. "It" is not necessary to makeallowances for an oilffilm on the surface of the condenser when they aredesigned.

The removal of the oil-filmallows reductions of as much as 25% in thearea of-the heat co'n-' ducting surface of the conductor withcorresponding savings inthe cost of the equipment? While theoil'separator comprising this in vention has been described in detail in"relation to specific forms of the invention, it is to be understoodthat the concept of this invention-is" not limited to those-specificforms, but is liinited only by the scope of the appended claims. Ii

I claim:

1. Apparatus for the separation ofoil fro'm a refrigerant dischargedfrom the -'compressor --or a refrigerating machine comprising '2, casinghaving an inlet and an outlet, an outlet tube extending into said casingfrom the outlet, a tubular bonded adsorbent block having a central boresurrounding said outlet tube, the central bore of the blockcommunicating with the inlet, a container mounted on the outlet tube, astrainer supported in the container, resiliently actuated closure meanspreventing by-passing of the adsorbent block and directing therefrigerant through said block and strainer to the outlet, and means fordischarging the separated oil from the casing.

2. Apparatus for the separation of oil from a refrigerant dischargedfrom the compressor of a refrigerating machine comprising a casinghaving an inlet and an outlet, an outlet tube extending into said casingfrom the outlet, a

- tubular bonded adsorbent block having a central bore surrounding saidoutlet tube, the central bore of the block communiucating with theinlet, a container mounted on the outlet tube, a strainer of cooper woolsupported in the container, resiliently actuated closure meanspreventing by-passing of the adsorbent block and directing therefrigerant through said block and strainer to the outlet, and means fordischarging the separated oil from the casing.

3. Apparatus for the separation of oil from a refrigerant dischargedfrom the compressor of a refrigerating machine comprising a casinghaving an inlet and an outlet, an outlet tube extending into said casingfrom the outlet, a tubular activated bonded alumina block having acentral bore surrounding said outlet tube, the central bore of the blockcommunicating with the inlet, a container mounted on the outlet tube, astrainer supported in the container, resiliently actuated closure meanspreventing by-passing of the adsorbent block and directing therefrigerant through said block and strainer mass to the outlet, andmeans for discharging the separated oil from the casing.

4. A separator for the separation of oil entrained in a refrigerantcomprising a casing having an inlet and an outlet in the upper endthereof, an outlet tube extending from the outlet nto the eatin andopeni g: downmazdlx .there in, an. adsoxbentbleck pQsit-iened, within;he ease na intermediate; the inlet; and theop nin ei the outlet; tubeiaiwell. the lower; end of? the e n o; receive the. liquid; cealesee in;he adsexhent. block through which; the. refrigerant: dischar ed; throughthe porous, block; passes. to the ou l tub and a float. operated, valvet o dis harge liquid. H m. the. well A separator for the, separatiqn of;o i;1 611,- tminedi in; a re ri erant comprising a. easing hey-- in an.inlet and an; outlet; the uppen end; them an; eutlet tubeextendin from;the, eutlet Lute the.- eesing, and. opening downwardly th m 1.11.11metallie wQol atminerhevihga larg 013.35:- aeetienel; area meuhtedi on.the; lower.- end, of the eutlet. tube. a perpue edsoxbent ble pesitieneiwithin th casin intermediate, the.- inlet: and the openin of he0ut1et-tuhe, awe11 in,the.-1owex'end: f. he; casin v to.- receive, the.liquid coalesced; in the. adsorbent block; through. which the; refrieran dischargedifrem the hloekpasses, and-afloat Qpemted, valve, todischarge liquid from the well.

6-. Apparatus: for the separation of; liquidifiom. gas in which; the.liquid is, entrained comprising: a casing having an inlet and an outletin. the upper-portion thereof,v a, porous block mounted within, theeasing, means within the casing; for directing the; gas, directly fromthe inlet; throu h 8:. the 9.011 25: blockwhereby; li -131mlw entrained.in, the gas: is eoeleseedtseie easing; h ng a well; in; lowelt portienfer e l eetinsrliqu d s parated t am.- the. as, a strainer meun ed; wiin e wales,- above th well. wher bycpal sced. r le s. of. liquid. dmninto the welL conduit means direet; ingthe a emer in fr m the p r usblock through, the strainer tn th qu e i d means for; disehar -ih th QleflfQm thewelL SQHILIWICK W. BAIQGS- BEEEBENQES CIIEED Thefollow-ingreferences are of recoi d in the file of this patent:-

SIAIES BA'ZENTS Number N me D te 1-.H% n-T-51 L M l L 1,280,765. Elm-B11 ten-eme- J tv L 1 1,780,156.: H ll; -,.,.-.-.L-.--.V-S- -.,,J=.e.Nevh, ,9119 2,048,993 Clafiey e a1; 4.-Iu1y' .935- 2;2 ,681 Bri gs WeJuly 18 ,1. 2,283,989 Henry 2,285,123,. lfhillipsv 2,341,430 E1syi-..-,v- F b- 8, .9 ,,4;

FOREIGN PATENTS Number Country 128, 18,

61,073 Germanyh -.--,-.-i June, 3.1228

